Diabetic retinopathy is the leading cause of blindness in the developed world. Its ability to cause the disease of blood vessels of the retina is the primary cause for blindness in both type 1 and type 2 diabetes patients. It’s time to take action and save your sight, warns Dr. Ho See Yunn, MBBS, Medical Officer, Singapore National Eye Centre.

Introduction

Diabetes Mellitus has more than what meets the eye – causing one to lose his or her sight. Almost all type 1 diabetes patients and 60% of type 2 diabetes patients have a certain degree of diabetic eye disease within twenty years of onset of the disease. On a more alarming note, a study by Wisconsin Epidemiologic Study of Diabetic Retinopathy showed that 3.6% of type I diabetics and 1.6% of type 2 diabetes patients were legally blind.

What is diabetic retinopathy?

To the public, Diabetes Mellitus usually brings with it images of amputated limbs, people with kidney failure undergoing dialysis and even the occasional heart attack. Sadly, the message of the complications of diabetic retinopathy has not been brought into focus. The primary reason could be because of the myriad of complicated terms that patients find hard to digest.

In simple terms, diabetic retinopathy is basically the disease of the retina – the photographic film at the back of the eye that a person’s visual images are focused upon. The macula is a particular spot on this ‘film’ that is responsible for our central vision. On the ‘film’ itself are many small vessels that deliver nutrients to it. Diabetes, being a disease of blood vessels, attacks the very walls of the vessels on the retina and causes the leakage of proteins and fats from these vessels.

The end result? Thickening of the wall of the retina and the macula, as what is termed medically, Macular Edema. This can lead to the loss of our central vision and the distortion of the images focused upon the retina.

Other complications include bleeding into the retina (retinal haemorrhages), formation of abnormal vessels (microaneurysms and venous beading) and, on a more serious note, formation of new blood vessels leading to bleeding into the vitreous jelly and detachment of the retina from the wall.

Screening for diabetic retinopathy

The dire consequences of complacency are enough to scare one into action. How does one get started? Firstly, it is recommended that for type 1 diabetes patients, first time screening of the eye should be done within three to five years of diagnosis of disease.

For type 2 diabetes patients, screening should be done at the time of diagnosis. The urgency is because many of these diabetes patients would have already had diabetes for six to seven years but have not had prior knowledge of it.

Screening of the eye involves taking photographs of the fundus of the eye and subsequent yearly follow-ups to record any progression of the disease. This can be done at the regular outpatient polyclinics or at the general practitioner’s clinics with the appropriate facilities.

When do I need to see the eye specialist?

So when does the diabetes patient see the ophthalmologist? Diabetic retinopathy is basically classified into non-proliferative and proliferative type. The former is divided into mild, moderate and severe depending on the classification of the retinal picture.

Referral to the ophthalmologist has to be made once the diagnosis of severe non-proliferative type or the proliferative type is made. This is to allow for the early intervention of laser to halt the progression of the disease before it bourgeons into more serious complications.

In addition, if the patient complains of sudden onset of worsening of vision and is found to have more serious complications like bleeding into the vitreous or even detachment of the retina, urgent referral to the ophthalmologist has to be made for surgery.

However, if the disease has already reached this stage, the visual prognosis would likely remain poor even with surgical interventions. Take action before it is too late.

Do I need to be follow-up regularly?

The story does not end here. Even with the intervention of laser and surgery, it is still crucial for the patient to continue follow-ups to monitor disease progression.

For the mild to moderate type of non-proliferative diabetic retinopathy, it is recommended to have follow-up every six to 12 monthly but for the severe type, it is recommended to have one to four monthly follow-ups. For the proliferative type, urgent laser treatment is needed. Always ask your family doctor for his or her recommendations for the duration of follow-up according to the clinical guidelines.

Take charge

You need to take charge and be responsible in ensuring that there is adequate and good control of the blood sugar level and blood pressure. Studies have shown that poor control of these two factors could worsen the progression of diabetic eye disease.

In diabetes patients with hypertension, it is recommended by the UKPDS study to have tight control blood pressure below 130/80mmHg to prevent diabetic complications.

Save your sight

Diabetes is a battle that can be fought if the proper armour is used. The same is true for diabetic eye disease. Armed with the above information, the patient and the physician can work hand in hand to prevent vision impairment. The message to the diabetic patient is clear – save your sight before it is too late.